1. Field of the Invention
The present invention relates to a light adjusting apparatus with a light adjusting section arranged in a space between substrates and a method for measuring a distance between substrates of the light adjusting apparatus.
2. Description of the Related Art
Image pickup apparatuses having an image pickup function are widely used in various fields, and in a field among them, small image pickup apparatuses, which have a relatively small shape, are used. Some examples of such small image pickup apparatuses include an electronic endoscope including a micro videoscope, an optical microscope provided with an image pickup function and a portable apparatus provided with an image pickup function.
With conventional small image pickup apparatuses, priority is given to miniaturization, and therefore a fixed focus lens, a fixed aperture diaphragm, a fixed characteristic filter or the like have been adopted as optical elements such as a lens, a diaphragm or an optical filter.
In contrast, high image quality is also required for such small image pickup apparatuses in recent years and a demand for adopting a focus lens, a variable diaphragm, a variable characteristic filter or the like, that is, a demand for functions as light adjusting apparatuses that adjust light as optical elements of the aforementioned light adjusting apparatuses, is growing.
Thus, many techniques for downsizing light adjusting apparatuses so as to be applicable to small image pickup apparatuses are proposed.
As an example, Japanese Patent Application Laid-Open Publication No. 10-20360 describes a configuration in which a coil body is arranged between an upper cover and a lower cover, and a rotor polarized into two poles by a magnetic field generated by the coil body is rotated. A diaphragm blade member is integrally and rotatably attached to the rotor via a shaft and the diaphragm blade member goes into or comes out of the optical axis as the rotor rotates to adjust incident light.